Methodology for detecting swallowing sounds

Abstract

The use of cervical auscultation in the evaluation of the pharyngeal swallow may become a part of the clinical evaluation of dysphagic patients. Though its use is based on subjective evaluation, an acoustic analysis of swallowing sounds might establish more objective criteria in the detection of swallowing disorders. The present study sought to investigate three aspects of the methodology for detecting swallowing sounds: (1) the type of acoustic detector unit suited to an acoustic analysis of the pharyngeal swallow, (2) the type of adhesive suited for the attachment of the detector, and (3) the optimal site for sound detection of the pharyngeal swallow. An accelerometer with double-sided paper tape was selected as the appropriate detector unit because of its wide range of frequency response and small attenuation level. Using this detector unit, swallowing sounds and noise associated with simulated laryngeal elevation and the carotid pulse were acquired at 24 sites on the neck in 14 normal subjects; these signals were acoustically analyzed. The determination of the optimal site for detecting swallowing sounds was based on the signal-to-noise ratio. The site over the lateral border of the trachea immediately inferior to the cricoid cartilage is the optimal site for detection of swallowing sounds because this site showed the greatest signal-to-noise ratio with the smallest variance. The site over the center of the cricoid cartilage and the midpoint between the site over the center of the cricoid cartilage and the site immediately superior to the jugular notch were also considered to be the most appropriate sites.

Methods for Detection and Classification of Normal Swallowing from Muscle Activation and Sound

“…As alternative to the acoustic analysis, tissue vibrations have been analysed [12]. However tation was applied to isolate the swallows.…”

“…The following sections of this paper will P inents evaluate solutions for these problems. [11], [12], [28]. Sound sound) during the recordings.…”

Doppler sonar analysis of swallowing sounds in normal pediatric individuals

“…Using an accelerometer, we scanned 24 neck sites. Of these, three were referred to use during neck auscultation, and the area on the lateral trachea, immediately below the cricoid was selected as the best site for swallowing sound detection 10 . The most prominent acoustic characteristic of the swallowing sound corresponding to food movement through the upper esophageal sphincter is found where the movements of the hyoid bone, the larynx and the epiglottis contributes to the swallowing acoustic signal 11 .…”

Signs for identifying risk factors for aspiration pneumonia in elderly people needing nursing care

“…Cervical auscultation (Takahashi et al, 1994) is a screening method for assessing swallowing function that can be performed relatively easily in nursing homes. The presence of wet hoarseness heard on auscultation has been pointed out by Warms et al to be associated with aspiration (Warms et al, 2000).…”